The present invention relates to fuel injection valves, in particular, an electromagnetic fuel injection valve suitable for an internal combustion engine.
Electromagnetically operated fuel injection valves for internal combustion engines are now widely used. A fuel injection valve of this type, is generally provided with a housing, an electromagnetic coil, a stationary core, a valve element with a movable core (anchor), a valve seat base, a valve holder, a return spring member and various intermediate/connecting elements. The movable core is adapted to be electromagnetically driven by the electromagnetic coil, and the valve member, connected to the movable core, is adapted for movement therewith into and out of sealing engagement with a valve seat. The spring member resiliently biases the movable core and the valve member toward the valve seat. When the electromagnetic coil is electrically energized, the movable core and the valve member are electromagnetically driven away from the valve seat against the spring force so that liquid fuel is forced out of the injector through the injector orifice into an associated internal combustion engine. When the electromagnetic coil is de-energized, the movable core is returned by the spring force so that the valve member is moved into sealing engagement with the valve seat to interrupt the injection of the liquid fuel.
The valve seat base is supported by the valve holder and the valve holder is typically coupled with the stationary core via the connecting elements which are made of non-magnetic material. The connecting element serves to guide the stroke of the anchor as well as seal fuel which resides between the core and the valve holder. The connecting element is made of non-magnetic material such that it would not interfere with the operation of the anchor, when one end of the anchor is magnetically attracted to one end of the stationary core.
The stationary core is welded to the connecting elements, which in turn, are welded to the valve holder, which in turn, is welded to the valve seat base. Hence, the conventional fuel injection valve has many parts, requiring increased weld points and associated production costs.
The present invention provides a fuel injector valve having reduced number of component parts requiring a reduced number of weld points.
In an object of the invention, a fuel injection valve is provided comprising a magnetic coil and a stationary core adapted to be magnetized upon energization of the magnetic coil. A movable core having one end opposed to one end of the stationary core is also provided, the movable core being movable toward the one end of the stationary core upon magnetization of the stationary core. Also, a valve element on the other end of the movable core is provided which is movable with the movable core to open and close a fuel injection port. The valve element is supported in a valve seat base. Further, a cylindrical body extending from at least the stationary core to the valve seat base is provided which guides the movable core and supports the base.